1. Field of the Invention
The present invention relates to a mechanical particle filter comprising a membrane having a multiplicity of pores, and to a method for manufacturing such a particle filter.
2. Background Information
Particle filters of this type are used to filter particles, for example bacteria, from a fluid. The particles filtered out can be analyzed in order to ascertain the pollution of the fluid with specific particles.
US 2003/0150791 A1 discloses a particle filter of the type mentioned in the introduction, wherein the membrane is formed from a silicon-based material. In order to form the pores, a mask material is applied to the silicon and small spheres are pressed into said mask material and displace the mask material at points. Afterward, the locations of the silicon membrane that have been uncovered in this way are etched open to create pores. Finally, the mask material is removed.
By contrast, U.S. Pat. No. 5,753,014 discloses a method for manufacturing a membrane filter, wherein a mask can be lithographically applied with the aid of a photosensitive layer. After exposure, the pores of the membrane are produced by etching.
DE 10 2006 026 559 A1 discloses the porosification of a substrate, for example composed of silicon, proceeding from the surface thereof, such that it is pervaded by thin channels or holes. This process can be adapted for example by electrochemical etching with light irradiation. As soon as the desired membrane thickness has been reached, the porosification process is ended.